Nut-fulcrumed pivoted jaw wrench



Sept. 11, 1951 D. F. HASTY NUT-FULCRUMED PIVOTED JAW WRENCH 2 Sheets-Sheet 1 Filed Feb. 12, 1946 I] lEli/VEIQTOR.

By J

ATTOFNfYS Sept. 11, 1951 D. F. HASTY NUT-FULCRUMED PIVOTED JAW WRENCH 2 Sheets-Sheet 2 Filed Feb. 12, 1946 INVENTOR. -F. H E% A 7' TO/PNEYS Patented sept. 11, 1951 N I TED STAT E S PATENT OFFICE NUT-FULCRUMED 'PIVOTED J AW WRENCH Dozier F. Hasty, Atlanta, "Ga.

Application February 12, 1946, Serial No. 647,140

1 Claim. 1

This invention relates to pipe wrenches of the plierstype, that is, wrenches in which'the clamping pressure is transmitted to the jaws by the squeezing together of the two handles associated with the respective jaws.

One of the objects of the invention is to provide a wrenchof the type described, in which the nut which adjusts the extent of opening of the jaws, itself acts as a fulcrum about which the movable jaw tilts in'clamping the pipe.

' Another object of the invention is to provide -a-wrench,--in which the adjusting nut, acting as the fulcrum, is so close to the plane of the fixed jaw 'as-to-give an extraordinarily high mechanical advantage.

Stillanother object of the invention is to pro- :V-idea wrench, as above described, in which there is a system of compound leverage between the handles and the point of clamping pressure.

' Other objects of the invention will appear as the following description of preferred embodiments thereof proceeds.

In the drawings which accompany and form :a part of the following specification:

Figure 1 is a side elevation, partly in section, showing one form of wrench embodying the broader principles of the invention;

J Figure2 is a bottom plan view;

Figure 3 i-s'a side elevation, partly in section, showing a modified form of the invention;

Figure 4 is a top plan view of the wrench shown in Figure 3.

Referring now in detail to the drawings, and first adverting to Figures 1 and 2, the handle I is preferably a straight member carrying at its forward end the fixed jaw 2. The handle 3 carries at-its' forward end the movable jaw 4. Integral with the handle '3 is a screw bar 5 which is perpendicular to the plane of the movable jaw 4 and extends through a slot 6 in the handle said slot "being wider ina fore and aft direction than the screw bar, so as to permit swinging movement of the latter. The slot 6 in its intermediate portion is expanded to form a recess I "within the handle *I, for housing the adjusting nut 8, with play to permit tilting movement of the adjusting nut with the screw bar 5 and having an upwardly extending projection 8 at the front forming a seat for the lower side of the flange I6 of the adjusting nut 8. The opposite sides of the recess 1 open through the sides of the handle I, exposing the sides of the adjusting nut 8, for manipulation and wide enough to permit the nut to be inserted therethrough in assembling the wrench. The adjusting nut is threaded on the screw bar.

The handle I is formed with a'longitudina'l slot '8, through which the handle 3 freely extends, the handle '3 being of bent form'so that itextends on'the opposite side of the handle I to the movable jaw i. The hand engageable portion it of the handle 3 is preferably straight and so disposed that when the jaws 2 and 4 are parallel, the hand engageable portion Ill lies partially within the slot 9 and substantiallyparallel to the handle -I. The handle I preferably has asupporting web I I within the slot -9 carrying a spring I2, which engages the hand engageable portion III of the handle 3 to prevent its going entirely into the slot I, when pressure is released'on the handle. The broken line showing of the handle 3 represents its released position. The full line showing represents its position when in clamped relationto a pipe between the jaws.

By virtue of the fact that the nut 8 is within the confines of the handle -I, and therefore close 'to the plane of the fixed jaw 2, the jaws remain in substantial parallelism throughout the range of width adjustment of the jaws while the hand engageable portion In of the handle 3 maintains substantial parallelism to the handle I. This means that regardless of whether a large or small size pipe is being gripped by the jaws, the distance between the hand engaging portions of the handles will be substantially constant.

It also adapts the wrench to be used in tightening or loosening nuts. The substantially parallel relation of the jaws distributes the pressure over the entire wrench faces of the nuts, preventing disfigurement due to localized pressure, while the parallel relation of the hand engaging portions of the handles and the fact that the handle 3 is for the most part within the slot 9 of the handle permits a pipe extension to he slipped over the handle :I, if necessary to gain additional leverage. The handle I is much sturdier than the handle 3 which it embraces, so that the handle I takes the strain incident to the use of the pipe extension.

The handle 3 is provided on its lower side with teeth 13, in that region which intersects the slot 9, and a lock bolt I4 slidably mounted in grooves I5 in the opposite side of the slot '9, may be engaged with the teeth I3 for locking the jaws 2 and 4 against the nut. If, when the jaws 2 and '4 are snugly against the opposite faces of the nut, the locking means should engage the handle 3 between adjacent teeth, a relatively slight additional pressure upon the hand engaging portion 1 0 of the handle 3 will cause the handle 3 to yield through its inherent resiliency sufficiently to permit the locking 'bolt to be slipped under the next tooth.

This locking arrangement is also useful when the wrench is employed as a pipe wrench to clamp the wrench to the pipe so that it will not fall off when manual pressure upon the handles is released.

In operation, the flange I6 of the adjusting nut 8 acts as a fulcrum, bearing against the upper wall of the recess 1 at the point I1 forwardly of the screw bar and below the fixed jaw 2. The operation is as follows. The width between the jaws is adjusted to the diameter of the pipe when the jaws are substantially parallel. The handles are then pressed together. This causes the movable jaw to swing slightly toward the fixed jaw, bearing down upon the pipe. The reaction pressure of the pipe tends to lift the movable jaw and with it to lift the forward side of the nut l6, pressing the forward part of the flange l6 against the upper wall of the recess 1 at the point I'I. Further pressure upon the handles causes the movable jaw to swing outwardly about the forward portion of the flange l6 as a fulcrum into clamping engagement with the pipe. From that point on, power for turning the pipe need be applied only to the handle I, as in-any pipe wrench. The fact that the fulcrum afforded by the forward part of the flange I6 is in front of the screw bar and close to the plane of the fixed jaw 2, gives the wrench an enormous mechanical advantage. For instance, if the vertical line through the fulcrum is at the point a and the vertical diameter of the pipe at the point I), onehalf inch in front of the point a, and the power end of the handle is ten inches long, then the mechanical advantage is twenty.

Referring now to that form of the invention illustrated in Figures 3 and 4, the handle I8 is similar to the handle I of the first described modification, in that it is straight; carries the fixed jaw I9 at its forward end; has a longitudinal slot 20 for the reception of the other handle 2|, and has a slot 22 therethrough to receive the screw bar 23 of the movable jaw 24, the slot 22 being larger in the longitudinal direction of the handle I8 than the screw bar, to permit fore and aft tilt of the latter.

The lower portion of the slot 22 is expanded to form areceiving chamber 25 for the adjusting nut'25. Said receiving chamber opens into the forward end of the slot 20. The handle I8 is provided with a bridge piece 21, intersecting the slot 20 near its forward end, said bridge piece being formed with a transverse cylindrical groove 28 forming a seat for the fulcrum of the handle 2|.

The latter handle plays within the slot 20, being bent so that the hand engaging portion 29 normally extends angularly from the top of the slot 20 when the wrench is in release position, and lies substantially within the slot 20 and parallel to the handle |8 when the wrench is in its final gripping position. A supporting web 30 carrying a leaf spring 3| is in the rear portion of the slot 2|], the spring supporting the handle 2| so that the hand engaging portion does not sink within the slot 20 when released.

The lever 2| has a transverse cylindrical rib 32 projecting from its under side adjacent its forward end, seating in the groove 28 and forming a fulcrum about which the lever 2| rocks. The forward end of the lever 2| has a cylindrical rib 33, extending into the nut chamber 25, and being in operative engagement with the adjustment nut.

. The adjustment nut 26 has spaced peripheral flanges 34 and 35 at its upper and lower ends,

Cir

defining between them an annular channel 35, into which the end of the lever 2| extends. The forward end of the handle l8 within the upper part of the nut chamber 25 is under-cut forwardly, forming a recess 31 which receives the forward portion of the upper flange 34, and defining a retaining lip 38 entering the forward part of the channel 36. The adjusting nut is threaded on the screw bar 23, and tilts with the latter.

The handle 2| is formed with an enlargement 39 circularly convex about the center of the fulcrum rib 32, and the handle I8 is provided with a retaining set screw 4|] which is adjusted to bear lightly upon the convex enlargement. By this means the handle 2| is retained in place and permitted to oscillate upon its fulcrum.

It will be readily understood from the above description that when the movable jaw 24 bears down upon a pipe positioned between the jaws. the reaction pressure of the pipe upwardly against the movable jaw lifts the forward part of the flange 34 of the adjusting nut against the upper wall of the recess 31, the point of contact being the fulcrum about which the adjusting nut, screw bar and movable jaw tilt in applying the clamping pressure. The adjusting nut thus becomes a lever having the forward portion 4| of the flange 34 as its fulcrum, the rearward portion 42 of said flange as its point of power application and some intermediate point at which the load is carried, the load being represented by the screw bar, movable jaw and the pressure of the movable jaw against the pipe. Power is applied to the rear portion 42 of the flange 34 by the forward end of the handle 2| which moves upwardly when the hand engaging portion 29 is pressed downwardly relative to the handle ll. Thus, the clamping pressure is applied through a system of compound leverage. If the ratio of the short arm d to the long arm 8 of the handle 2| to 1 to 10, and the load point is at one-half the distance of the fulcrum 4| to the point of power application 42 of the adjusting nut, then the ratio of power application is 1 to 20.

With respect to both of the illustrated forms of range, it will be readily understood that since a different circumferential point of the fulcrum flange of the adjusting nut would be presented at the point of fulcrum for each position of the movable handle, the fulcrum flange will be subjected to very little wear and tear, and will last indefinitely. In the case of the double flanged adjusting nut, in that form of the invention shown in Figures 3 and 4, it may be reversed so that the lower flange becomes the fulcrum.

It will be noted from Figure 3 that the intermediate portion 43 of the handle 2| is inclined to the adjacent portions of the handle at a small angle, and it will be understood that when the wrench is in clamping engagement with a pipe or nut with the jaw faces parallel, the handle 2| will be in a position approaching that shown in full lines in Figure 3, so that the inclined intermediate portion 43 will make a small angle with the longitudinal dimension of the handle 2|. The opposite walls of the slot 20 are provided near the top of said slot with the track grooves 44, in which slides a locking bolt 45 forwardly of the inclined portion 43 of the handle 2|, and which may be brought into engagement with said inclined portion. Due to the small angle of inclination of said portion relative to the path of movement of the locking bolt, the latter will stick at the point at which it makes contact with said inclined portion.

In disassembling either wrench it is simply necessary to unscrew the adjusting nut until it is freed from engagement with the screw bar. In that form shown in Figure 1, the adjusting nut is then simply pushed sidewise out of one of the open sides of the recess 1. In that form shown in Figures 3 and 4, both the handle 2| and screw bar 23 must be removed to release the adjusting nut. To remove the handle 2|, the set screw 40 is loosened sufficiently to permit the fulcrum rib 32 to be disengaged from its seat 28. After the handle 2| has been removed, the adjusting nut is still held in place by the screw bar since the tilt of the latter in the direction indicated in broken lines in Figure 3 is limited by contact of the forward side of the screw bar with the adjacent wall of the slot 22, said wall acting as a stop. At this maximum angle of tilt the adjusting nut cannot escape from the recess 31. When the screw bar 23 is removed the nut can be further inclined so as to slip out of the recess 31 and drop through the open bottom of the chamber 25.

While I have in the above description disclosed what I believe to be preferred and practical embodiments of the invention, it will be understood to those skilled in the art that the details of construction and arrangement of parts as shown, are illustrative and not to be construed as limiting the scope of the invention.

What I claim as my invention is:

In a wrench, cooperating fixed and movable jaw members, the fixed jaw member comprising a jaw at its forward end and a handle rearwardly of said jaw, said handle being longitudinally slotted, the movable jaw member comprising a jaw confronting the jaw of the fixed member, and a screw unitary therewith perpendicular to said movable jaw extending through a forward slot in said fixed jaw member with tilting play in a fore and aft direction, the lower part of said forward slot being expanded into a nut receiving recess having a transverse groove in its wall forward of said screw, a nut in said recess engaging said screw for operating the latter to adjust the width of the opening between the jaws, said nut having an upper peripheral flange extending into said groove, by the lower wall of which groove the forward part of said nut is normally supported, said nut being tiltable with said screw, having a point in its upper periphery bearing against the upper wall of said groove as a fulcrum, and a handle for said movable jaw member consisting of a lever fulcrumed intermediate its ends in the longitudinally slotted portion of the handle of said fixed jaw member by means of a transverse cylindrical fulcrum rib on its under side seated in a correspondingly shaped seat in said handle, having its forward end engageable with said peripheral flange at a point rearward of said screw for tilting said nut together with said movable jaw member about said ,fulcrum to gain clamping pressure upon an object embraced by said jaws, said lever having on its upper side a transversely cylindrical face coaxial with said fulcrum riband retaining means carried by said handle bearing slidably against said cylindrical face for retaining said lever.

DOZIER F. HASTY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS G e B it in Dec. 9, 9 1 

